In the present study, vortex-assisted matrix solid-phase dispersion (VA-MSPD) extraction was used to isolate the major bioactive compounds from H. arenarium. To reduce the negative environmental impact of the conventionally used organic solvents, four different choline chloride-based natural deep eutectic solvents (NADES) were investigated as possible eluents. The most influential VA-MSPD extraction parameters: stationary phase (adsorbent), adsorbent/sample ratio, vortex time, and volume of extraction solvent were systematically optimized. Ultrasound-assisted extraction with 80% MeOH was used as the standard method for the comparison of results. The stability of the obtained extracts was studied over a period of 0 to 60 days at three different temperatures (−18 °C, 4 °C, and 25 °C). All extracts were evaluated both spectrophotometrically (determination of total phenolic content (TPC) and antioxidant activity by ABTS and FRAP assay) and chromatographically (HPLC-UV). NADES based on choline chloride and lactic acid (ChCl-LA) was selected as the most effective extractant, with a determined TPC value of its extract of 38.34 ± 0.09 mg GA/g DW (27% higher than the methanolic VA-MSPD extract) and high antioxidant activity. The content of individual phenolic compounds (chlorogenic acid, dicaffeoylquinic acid isomers, naringenin isomers, and chalcones) in the ChCl-LA extract, determined by HPLC-UV, was comparable to that of the conventionally obtained one. Moreover, the stabilization effect of ChCl-LA was confirmed for the studied compounds: chlorogenic acid, naringenin-4′-O-glucoside, tomoroside A, naringenin-5-O-glucoside, isosalipurposide, and naringenin. The optimum VA-MSPD conditions for the extraction of H. arenarium polyphenols were: florisil/sample ratio of 0.5/1, a vortex time of 2 min, and an elution volume of ChCl-LA of 10 mL.
Circulation of the Omicron variant with the reemergence of the N501Y mutation along with many others in the spike protein has once again stirred the academic community. Interestingly, tracing the genetic diversity of SARS-CoV-2 shed light on a less frequent N501Y + Delta variant which has been in the global circulation for some time before the Omicron appearance. This paper aims to present the molecular characteristics of the SARS-CoV-2 Spike_N501Y + Delta variant detected in Bosnia and Herzegovina. The study was conducted during November and December 2021. All patients were tested using real-time RT-PCR for detection of SARS-CoV-2. A representative number of SARS-CoV-2 positive samples was pre-screened using VirSNiP SARS-CoV-2 Spike N501Y kit. The characterization of the viruses was carried out with Illumina RNA Prep with enrichment and the Respiratory Virus Oligo Panel kit. Among the analyzed sequences, we found two isolates of the Delta variant that differ from their most related clade- GK AY.4.3 in additional mutations N501Y and L54F. In this study, we described the presence of a rare form of Delta variant with Spike_N501Y mutation in the shadow of the Omicron emergence. Despite the set of mutations in the Spike protein, this form of Delta variant does not indicate the large-scale consequences for the general population. Further functional studies of this form could provide more information about its antigenicity and infectivity.
This study analyzed 16 bisphenols (BPs) in wastewater and sludge samples collected from different stages at a municipal wastewater treatment plant based on sequencing batch reactor technology. It also describes developing an analytical method for determining BPs in the solid phase of activated sludge based on solid-phase extraction and gas chromatography-mass spectrometry. Obtained concentrations are converted into mass flows, and the biodegradation of BPs and adsorption to primary and secondary sludge are determined. Ten of the sixteen BPs were present in the influent with concentrations up to 434 ng L−1 (BPS). Only five BPs with concentrations up to 79 ng L−1 (BPA) were determined in the plant effluent, accounting for 8 % of the total BPs determined in the influent. Eleven per cent of the total BPs were adsorbed on primary and secondary sludge. Overall, BPs biodegradation efficiency was 81%. The highest daily emissions via effluent release (1.48 g day−1) and sludge disposal (4.63 g day−1) were for BPA, while total emissions reached 2 g day−1 via effluent and 6 g day−1 via sludge disposal. The data show that the concentrations of BPs in sludge are not negligible, and their environmental emissions should be monitored and further studied.
In the present-day environment pertaining to digitalisation, increasing competition on the market and changes in industries, the CRM as a system is an essential tool for success. The issue of CRM system application in higher education institutions is insufficiently researched, especially in the parts that should indicate a clear connection between participants in higher education and CRM in higher education institutions, and factors that decision makers should pay attention to when making decisions about CRM implementation. Therefore, the aim of the paper is to research the functionality, application and advantages of CRM in the higher education sector, and to determine the features that will facilitate effective decision-making on the implementation of CRM. As a result of the research, a proposal for a conceptual model/framework of CRM was presented. The proposal is presented for the purpose of making appropriate decisions for higher education institutions when it comes to developing their own or purchasing a ready-made CRM solution. From the scientific aspect, the paper contributes to the existing literature by providing decision makers with an insight into the structure of the CRM system, its elements, connections and functionalities, as well as a description of the model with the information they need to pay attention to when making decisions.
Abstract The subject of this paper are the diary no- tes of the Bavarian botanist Otto Sendtner published in the German magazine "Das Ausland" regarding the medieval fortress of Srebrenik and the tradition about its fall under the Ottoman rule, which were completely unknown in the literature. This Munich university professor stayed in the Bosnian ejalet/Province in 1847, and on that occasion, he visited a significant number of cities, starting with Split, Livno and Travnik as the main destination. From the vizier's city and the seat of Ejalet, he went to Bosanska Posavina due to his botanical research, and on that occasion he passed through Srebrenik. Sendtner wrote in detail about the fortress, inspired by its features, and also left a note of local folklore tradition regarding its fall under the Ottomans, which deserves special attention. Also, in Send- tner's exposition, romantic narratives and orientalism ele-ments can be observed in the descriptions of the Srebrenik fortress and the landscape surrounding it, which can be attributed to the features of the imagi- nation about the Middle Ages presented in the European intellectual circles during the middle of the 19th century. Keywords Srebrenik, Bosnia, Middle Ages, oral tradition, travelogue, Otto Sendtner
Ensuring safety is of paramount importance in physical human-robot interaction applications. This requires both adherence to safety constraints defined on the system state, as well as guaranteeing compliant behavior of the robot. If the underlying dynamical system is known exactly, the former can be addressed with the help of control barrier functions. The incorporation of elastic actuators in the robot's mechanical design can address the latter requirement. However, this elasticity can increase the complexity of the resulting system, leading to unmodeled dynamics, such that control barrier functions cannot directly ensure safety. In this paper, we mitigate this issue by learning the unknown dynamics using Gaussian process regression. By employing the model in a feedback linearizing control law, the safety conditions resulting from control barrier functions can be robustified to take into account model errors, while remaining feasible. In order to enforce them on-line, we formulate the derived safety conditions in the form of a second-order cone program. We demonstrate our proposed approach with simulations on a two-degree-of-freedom planar robot with elastic joints.
The asphalt layer is an important financial part of the total cost of road infrastructure, so it is necessary to analyze and consider all the elements that may affect the quality of the same. One of them is certainly the influence of temperature during the installation of asphalt mass. Namely, neither high nor low temperature of asphalt and the environment are favorable for its installation, so it is necessary to find optimal conditions for the installation of asphalt in order to achieve the best possible results of compaction and cavities in the asphalt layer. The aim of this research is to find the optimal conditions for its installation by comparative analyzes of different temperatures of the asphalt mixture and the environment, in order to obtain the lowest percentage of cavities in the asphalt layer. The legal regulations, ie technical conditions, define the minimum temperature of the asphalt mixture as well as the limit air temperature during the installation of asphalt, but special emphasis is placed on the impact of the temperature of the asphalt installation on the cavities in the asphalt layer. Therefore, the paper observes the optimal temperature of the asphalt mixture so that the smallest possible percentage of cavities in the asphalt layer is obtained. Keywords: asphalt mixture temperature, installation, cavities
In this paper, it was necessary to prove that Semberija is in the geomorphological sense, the southern part of the Pannonian Basin, which is in contact with the Dinaric mountain system. Its done on the basis of the geo- morphological analysis of the terrain, primarily morphotectonic, morphological and morphogenetic similarities with the plain terrain of Pannonia. This was the basis for a complex geomorphological regionalization which included added similarities and connections with the Pannonian Basin in climate, pedogeography and biogeog- raphy sense. Thus, after the complex geomorphological regionalization, it was determined that Semberija is a meso-entity, a subunit of the geomorphological macroregion Sava Basin, ie the southernmost part of the geo- morphological megaregion Pannonian Basin. Key words: Complexed geomorphological regionalization, geomorphological meso-entity Semberija lowland plain, Pannonian Basin, Bosnia and Herzegovina.
. We obtain a meromorphic continuation of the generalized Tribonacci zeta function to the whole complex plane. The residues of the generalized Tribonacci zeta functions associated to the third-order Jacobsthal, Tribonacci and Narayana sequence at negative inte-ger poles are computed.
Students’ learning outcomes in physics are significantly affected by the quality of outside-of-classroom learning experiences. A rich source of these experiences may be the physics homework. In this study, the effects of technologically-rich physics homework were evaluated. To that end a pretest-posttest experimental design has been used. 67 first-year students from the First Bosniak Gymnasium were randomly assigned to one of the three homework approaches. In the control group students received conventional homework about work and energy. Within the simulation-based approach students were expected to interact with simulations to investigate work and energy phenomena, whereas in the video-based approach students learned by analyzing a video in which the teacher interacted with the same simulations as mentioned above. Based on analysis of covariance we could find that the between-group differences on the conceptual posttest were not statistically significant, F(2, 47)=0.59, p=0.56. At the same time, students who learned by interacting with simulations expressed significantly more positive attitudes towards homework, compared to students from the video-based group (mean difference=1.88, p=0.038), as well as compared to students from the conventional group (mean difference=2.02, p=0.03). Simulation-based physics homework may be a powerful tool for helping the students to reach important affective learning outcomes.
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